Hydraulically operated access equipment

ABSTRACT

Hydraulically operable access equipment, usually but not necessarily vehicle mounted, and of the kind comprising a boom structure consisting of a plurality of booms pivotally connected together in end to end relationship, hydraulic actuators with an associated hydraulic control system for moving the boom structure between a stowed position wherein at least some of the booms lie parallel with one another in a substantially horizontal direction and an extended position wherein the free end of the boom structure is raised to an elevated position, characterised by the provision of secondary, normally closed, inlet and outlet ports to the oil chambers of at least some of the hydraulic actuators, and an auxiliary system comprising a pump and flexible hoses capable of being extended from such pump for connection to the secondary inlet and outlet ports of each said actuator, whereby such actuators may be operated to permit movement of the boom structure to its stowed position by use of said auxiliary hydraulic system.

United States Patent [1 1 I Ashworth Dec. 11, 1973 1 HYDRAULICALLY OPERATED ACCESS [73] Assignee: Simon Engineering Limited, Dudley,

England [22] Filed: Apr. 10, 1972 [21] Appl, No.: 242,706

[30] Foreign Application Priority Data Primary Examiner-Reinaldo P. Machado Attorney-James E. Nolan et al.

[57] ABSTRACT Hydraulically operable access equipment, usually but not necessarily vehicle mounted, and of the kind comprising a boom structure consisting of a plurality of booms pivotally connected together in end to end relationship, hydraulic actuators with an associated hydraulic control system for moving the boom structure between a stowed position wherein at least some of the booms lie parallel with one another in a substantially horizontal direction and an extended position wherein the free end of the boom structure is raised to an elevated position, characterised by the provision of secondary, normally closed, inlet and outlet ports to the oil chambers of at least some of the hydraulic actuators, and an auxiliary system comprising a pump and flexible hoses capable of being extended from [56] References Cited 'such pump for connection to the secondary inlet and UNITED STATES PATENTS outlet ports of each said actuator, whereby such actu- 3,528,524 9/1970 Birbanescu 182/2 my be operated to permit movement of the boom structure to its stowed position by use of said OW 6S 3,633,363 111972 Larsen 91/6 auxhary hydraullc System- 3,213,948 10/1965 Eckels 182/2 6 Claims, 2 Drawing Figures o fi O I o o g This invention concerns hydraulically operable access equipment, usually but not necessarily vehicle mounted, and of the kind (hereinafter termed of the kind referred to) comprising a boom structure consisting of a plurality of booms pivotally connected together in end to end relationship, hydraulic actuators with an associated hydraulic control system for moving the boom structure between a stowed position wherein at least some of the booms lie parallel with one another in a substantially horizontal direction and an extended position wherein the free end of the boom structure is raised to an elevated position. Normally the free end of the boom structure will carry a working platform or cage whereby an operator can be raised to such elevated position.

Hydraulically operable access equipment is now widely used for numerous industrial, maintenance and service applications such as fire fighting for example. Generally such equipment is highly reliable but failure of one part or another of the hydraulic system is not unknown.

It is known to provide means for unlocking lock valves on hydraulic rams or for bleeding oil therefrom to permit the booms to be lowered under the influence of gravity. In many instances however it is necessary first to raise the boom structure before it can be lowered as for example if the boom structure is extending over a roof and between two chimneys, when of course such known means are ineffectual.

It is an object of the present invention to provide an auxiliary hydraulic system to enable the hydraulic actuators to be operated to permit movement of the boom structure to its stowed position in the event of failure of any part of the main hydraulic system other than the essential working parts of the hydraulic actuators themselves.

According to the present invention hydraulically operable access equipment of the kind referred to is characterised by the provision of secondary, normally closed, inlet and outlet ports to the oil chambers of at least some of the hydraulic actuators, and an auxiliary hydraulic system comprising a pump and flexible hoses capable of being extended from such pump for connection to the secondary inlet and outlet ports of each said actuator, whereby such actuators may be operated to permit movement of the boom structure to its stowed position by use of said auxiliary hydraulic system.

Preferably the free ends of said hoses are equipped with coupling means adapted to be connected instantly to said secondary ports.

The invention will be further apparent from the following description with reference to the figures of the accompanying drawing which show, by way of example only, one form of hydraulically operable access equipment embodying the invention.

Of the drawings:

FIG. 1 shows a diagrammatic side elevation of the equipment;

and FIG. 2 shows a side elevation of one of the hydraulic rams of the equipment of FIG. 1, on an enlarged scale.

Referring firstly to FIG. 1 it will be seen that the equipment comprises, in known manner, an articulated boom structure, generally indicated at 10, mounted on the chassis of a vehicle 11. The boom structure comprises a first boom 12 whose root is pivotally connected to a turntable structure 13 secured to the vehicle chassis, and a boom 14 pivotally connected to the other end of the boom 12, and carrying at its free end a working platform or cage 15 for an operator. An hydraulic motor is provided to effect rotation of the turntable structure 13, and double acting hydraulic rams 16 and 17 are provided and pivotally connected between the structure 13 and boom 12, and booms l2 and 14 respectively. It will be understood that the rams l6 and 17 may be actuated to move the boom structure between its stowed position (as illustrated in FIG. 1) wherein the booms I2 and 14 lie substantially horizontally in superimposed relationship, to a working position wherein the cage 15 is elevated giving the operator access to a position remote from the ground. The vehicle 11 is equipped with extendable and retractable ground engaging stabilising jacks 18 which are operated by further hydraulic rams (not shown) to ensure that the vehicle is in a stable condition when the boom structure is to be raised.

All of the hydraulic actuators are controlled by means of a main hydraulic pump 19 and control valves (not shown) located in the cage 15. In accordance with the invention an auxiliary hydraulic system is provided selectively to operate any one of the various hydraulic actuators whereby the boom structurecan be moved from an elevated position to its stowed or travelling position, and the ground engaging jacks l8 retracted to permit the vehicle 11 to be moved, in the event of any failure of the pump-19, the control valves or lines connecting these parts with the actuators themselves. Thus, a secondary hydraulic pump 20 is provided. The pressure outlet and return flow inlet ports of the pump 20 are connected with flexible hoses which are normally stowed on reels 21 and 22 respectively. Each of the hoses is of such length as to ensure that its free end can be carried to the vicinity of the most remote actuator when such actuator is in its most remote position relative to the pump 20 by virtue of the configuration of the boom structure.

Each of the hydraulic actuators is equipped with secondary, normally closed, inlet and outlet ports communicating with the oil chambers thereof, and the free ends of the flexible hoses are adapted to be coupled directly with these ports by instantly and manually operable snap-on connectors.

By way of example and referring to FIG. 2 it will be seen that the double acting hydraulic ram 16 is provided with normal pressure fluid inlet and outlet lines 23 and 24 respectively and auxiliary ports 25 and 26 adapted to be communicated with the oil chambers on either side of the piston thereof when connected with the flexible hoses from reels 21 and 22.

It will be appreciated that in the event of any failure of the main hydraulic system the hoses from reels 21 and 22 can be extended and connected to the secondary ports of any required hydraulic actuator to enable same to be operated and hence to permit the boom structure to be moved to its stowed or travelling position and the ground engaging jacks to be raised.

Preferably the equipment includes means to enable the operator to have direct access to each of the actuators for the purpose of connecting the flexible hoses therewith without the necessity of any special equipment. Such means preferably comprises ladder means 3 28 extending alongside the booms and movable therewith.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without departing from the scope thereof.

What is claimed is:

1. l-lydraulically operable access equipment of the kind wherein a boom structure comprises at least two booms pivotally connected together with one end of, one of said booms movably mounted on a support, said booms being movable between a stowed position on said support and extended working positions. at least one hydraulic actuator is connected between said one boom and said support and at least one hydraulic actuator is connected between said booms, and a main hydraulic system having a main pump is connected to operate said actuators to normally move said booms between said positions, characterized by the provision of secondary, normally closed, inlet and outlet ports to the hydraulic fluid chambers of said hydraulic actuators, and an auxiliary hydraulic system comprising a secondary pump and flexible hoses connected at one end to said secondary pump and of such length as to be capable of being extended from such secondary pump for connection to the secondary inlet and outlet ports of each said actuator with said booms in or between said positions, whereby such actuators may be operated to permit movement of the boom structure to its 4 stowed position by use of. said auxiliary hydraulic system.

2. l-lydraulically operable access equipment according to claim 1 wherein the free ends of said hoses are equipped with coupling means adapted to be connected instantly with said secondary actuator ports.

3. l-lydraulically operable access equipment according to claim 1 wherein said boom structure is mounted on a turntable adapted to be rotated by a hydraulic motor said motor being provided with secondary, normally closed, inlet and outlet ports whereby it may be actuated by use of the auxiliary hydraulic system.

4. Hydraulically operable access equipment according to claim 1 including hydraulically operable extendable and retractable ground engaging stabilising jacks whose hydraulic actuators are provided with secondary, normally closed, inlet and outlet ports whereby said jacks may be operated by use of said auxiliary hydraulic system.

5. l-lydraulically operable access equipmentv according to claim 1 including ladder means carried by the booms to give an operator access to any of the hydraulic actuators for the purpose of coupling said flexible hoses therewith.

6. The hydraulically operable access equipment defined in claim 1, including reel means on the support for storing said hoses during normal operation by the main hydraulic system.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,777,845 Dated Dec. 11, 173

ln nt fl D'eni s Henrv Ashworth It is certified that erx 'or appears in the above-identified patent I and that said Letters Patent are hereby corrected as shown below:

The assignee should read --.-Simon Engineering Dudley Limited-- A Signed and sealed this, 7th day of May 197A.

(SEAL) Atte st:

EDWARD I'LFLETGHERQJR. 4 c. MARSHALL DANN Attesting Officer Commissioner of Patents FORM P0-1O5O(1O-69) USCOMWDC 5037M, 

1. Hydraulically operable access equipment of the kind wherein a boom structure comprises at least two booms pivotally connected together with one end of one of said booms movably mounted on a support, said booms being movable between a stowed position on said support and extended working positions, at least one hydraulic actuator is connected between said one boom and said support and at least one hydraulic actuator is connected between said booms, and a main hydraulic system having a main pump is connected to operate said actuators to normally move said booms between said positions, characterized by the provision of secondary, normally closed, inlet and outlet ports to the hydraulic fluid chambers of said hydraulic actuators, and an auxiliary hydraulic system comprising a secondary pump and flexible hoses connected at one end to said secondary pump and of such length as to be capable of being extended from such secondary pump for connection to the secondary inlet and outlet ports of each said actuator with said booms in or between said positions, whereby such actuators may be operated to permit movement of the boom structure to its stowed position by use of said auxiliary hydraulic system.
 2. Hydraulically operable access equipment according to claim 1 wherein the free ends of said hoses are equipped with coupling means adapted to be connected instantly with said secondary actuator ports.
 3. Hydraulically operable access equipment according to claim 1 wherein said boom structure is mounted on a turntable adapted to be rotated by a hydraulic motor said motor being provided with secondary, normally closed, inlet and outlet ports whereby it may be actuated by use of the auxiliary hydraulic system.
 4. Hydraulically operable access equipment according to claim 1 including hydraulically operable extendable and retractable ground engaging stabilising jacks whose hydraulic actuators are provided with secondary, normally closed, inlet and outlet ports whereby said jacks may be operated by use of said auxiliary hydraulic system.
 5. Hydraulically operable access equipment according to claim 1 including ladder means carried by the booms to give an operator access to any of the hydraulic actuators for the purpose of coupling said flexible hoses therewith.
 6. The hydraulically operable access equipment defined in claim 1, including reel means on the support for storing said hoses during normal operation by the main hydraulic system. 